Method and apparatus for applying oblique spray



May 6, 1952 L. PDOSMANN METHOD AND APPARATUS FOR APPLYING OBLIQUE SPRAY Filed July 30, 1948 Patented May 6, 1952 METHOD AND APPARATUS FOR APPLYING OBLIQUE SPRAY Lucian P. Dosmann, South Bend, Ind., assignor to Mishawaka Rubber and Woolen Manufacturing Company, Mishawaka, Ind., a corporation of Indiana Application July 30, 1948, Serial No. 41,528

My invention relates to the spraying of continuously advanced flexible sheet material with a spray which is directed at an acute angle to the direction in which the sheet is passed through the spraying zone and has reference more particularly to a method of and apparatus for applying the sprayed particles perpendicularly on the sheet.

In quantity production of spray surfaced flexible sheet materials, it is customary to pass the sheet material in a continuous manner through the spraying zone.

Moreover, it has been found advantageous and desirable, not only for the purpose of avoiding wastage of the spraying material due to overspray beyond the margins of the sheet, but also for the purpose of greater uniformity of spray application across the width of the sheet, to employ electrostatic control ofthe character disclosed in Ransburg Patents 2,247,963, 2,270,341, 2,334,648 and 2,428,991.

In accordance with the principles of said patents, charged electrodes of like polarity, are arranged at opposite sides of the path of the spray so as to create between the electrodes an electrostatic field in which the sprayed particles become charged with electricity of that same polarity, and an electric charge of opposite polarity is impressed on the -article or material to be sprayed so that said article or material attracts the charged particles of the spray thereto.

For effective electrostatic control in spraying sheet material which is continuously advanced through the spraying zone, the spraying devices are arranged to discharge at an acute angle to the direction of movement'of the sheet material so that the direction of spray is somewhat length- Wise of the moving sheet and of the electrodes, which latter are located just beyond the lateral margins of the sheet and extend a considerable distance along the path of the sheet to insure suiiiciently prolonged exposure of the sprayed particles to the electrostatic eld to become adequately charged.

In some sheet spraying operations, however, for example, in making sprayed latex sheet materials,

such as disclosed in co-pending applicationI Serial No. 550,964, noW Patent 2,501,839, granted March 28, 1950, which I filed jointly with Virgil I-I. Bodle and George W. Blair, wherein the sprayed particles are accumulated or piled up on the sheet in somewhat individualized formations simulative of tufted or pile carpeting, while the electrostatic'control of the spraying is quite desirable in order to' avoid vvastagel of the latex and 6 Claims. (Cl. 117-93) to contribute uniformity to the spraying across the width of the sheet, the angularity of the spraying, somewhat lengthwise of the sheet, which is required for the electrostatic control, causes a building up of the tuft or pile simulative formations at an undesirable inclination toward the source of the spray so that they appear to lean in that direction, whereas it is desirable that the formations be upright or perpendicular to the surface of the sheet.

Moreover, it is important in making sheet materials with such sprayed formations, that the sprayed particles be applied to the sheet perpendicularly as better attachment thereof is effected thereby and a surfacing of better wearing properties is obtained.

The principal objects of my invention are to provide an improved method and improved facilities for spraying on sheet material a surfacing simulative of tufted or pile carpeting; to insure perpendicular applicationon a sheet of particles which are sprayed in a direction non-perpendicular to the direction in which the sheet is passed through the spraying zone; and to provide an `improved method and improved facilities for electrostatic spraying, these and other objects being accomplished as pointed out more fully hereinafter and as shown in the accompanying drawing, in which:

Fig. l is a top view of equipment for spraying sheet material in accordance with my invention;

Fig. 2 is a view taken on the line 2 2 of Fig. 1;

Fig. 3 is a View of the equipment of Fig. 2 taken substantially on the line 3-3 of Fig. 2;

Figs. 4 and 5 are sectional and top views respectively of spray surfaced material simulative of tufted or pile carpeting as made in accordancev with the present invention; and

Figs. 6 and 7 are views corresponding respectively to Figs. 4 and 5 and showing simulative tufted or pile carpeting material as made with electrostatically controlled spraying equipment like that of Figs. 1, 2 and 3 but without the facilities of the present invention for perpendicular application of the spray.

Referring to the drawing which is illustrative of a preferred form of equipment for making a sprayed surfacing which simulates tufted or pile carpeting, the reference numeral Il indicates a conveyerbelt, which is made of rubber coated fabric, andA operated continuously in the direction indicated by the arrows in Figs. 1 and 2 to support and convey flexible sheet material l2 horizontally through a zone wherein the surfac- 3 ing is sprayed onto the top surface of the shee material I2.

For making a surfacing, such as referred to particularly hereinbefore and illustrated at I3 in Figs. 4 and 5, which simulates tufted or pile carpeting. a coagulable dispersion, such as latex, is employed and sprayed, together with a spray of suitable coagulant, onto the sheet I2 as the latter is carried by the conveyer II through the spraying zone.

The spray is electrostatically controlled in a manner hereinafter described. and for effective electrostatic control the latex and coagulant spray nozzles are arranged substantially as shown in Figs. l, 2 and 3 wherein I4 and I5 indicate upper and lower latex spray nozzles respectively, and I6 a coagulant spray nozzle, each of which nozzles is located in a plane midway between the lateral margins of the belt I I and produces a fan-like spray extending flatwise across and of suicient spread to cover the width of the sheet material- I2 on the conveyer belt.

The lower latex nozzle I5 is positioned to spray horizontally in-the'direction of movement of the conveyor belt II and the coagulant nozzle I6 is located directly above the horizontal nozzle I6 andarranged to discharge at an angle of approximately tothe horizontal plane of the belt I I`,the elevation of said nozzle I6 being such that the plane of discharge of the spray from the AnozzleVII intersects the belt at substantially the location indicated at I1 in Fig. 2.

The upper-latex nozzle I4 is located at the front of and at an elevation above the coagulant nozzle I6, 'and is directed at an angle of approximately 30 to the plane of the belt II, the ari rangement being such that the plane of discharge of the sprayV from said nozzle I4 intersects the belt at substantially the same place I1 as the spray plane of the coagulant nozzle I6.

nozzles I4,A I5 and I6, a pairof corresponding long electrodes I8 are provided which extend respectively along the lateral margins of the belt from a transverseplane just behind the upper latex nozzle I4 to a transverse plane substantially beyond the place I1 where the spray planes of the-Y two nozzles .I4 and I6 intersect the belt I I, as indicatedin Fig. 2,.said electrodes being suspended by hangers I9 and in an insulated manner, through insulators 22, at substantially the same elevation above the belt II as the nozzle I5.

Each said electrode I8 comprises a wire frame of electrically conductive wire with upper and lower lengths 23 and 24 Vrespectively of the wire joined together somewhat closely at the ends remote from thenozzles, as indicated at 25, and diverging toward the nozzle ends where these upper and lower lengths 23 and 24 are connected by outwardlyflared wire loops 26. Spaced cross wires 21 'also connect the lower wire lengths 24 at the end of the electrodes remote from the nozzles as indicated in Figs. l, 2 and 3.

These electrodes I8 which are electrically connected together by the cross wires 21 are connected by a conductor. 28 to the negative pole of a high potential direct current generator 29, the

4 other positive pole of which is grounded as indicated at 30.

Metal frame members 3I extend along the lateral margins of the belt II at the spraying zone and support a metal plate 32 upon which the conveyor belt II slides and this metal plate 32 and the frame members 3I are grounded through the ground connection 33 so as to receive a positive charge from the grounded positive pole of the generator 29.

Thus, when the generator 29 is in operation and latex and coagulant are sprayed from the respective nozzles I4, I5 and I6, the electrodes I8 and their cross Wires 21 are negatively charged and create a negative field between the electrodes and around the cross wires 21 which imparts' a negative charge to the latex particles and coagulant sprayed from the nozzles I4, I5 and I6, and when the particles are thus charged, the corresponding negative polarity of the electrodes I8 and cross wires 21- provide a barrier veffect by which the sprayed particles are connedfto the zone over the belt I I and wastage of latex due to overspray beyond the lateral margins ofr the belt is thus substantially avoided.

Moreover, the confinement or localization-of the spray over the belt II is furtherwpromoted by the positive polarity of the belt underlying plate 32 which therebyl has an attraction Vfor the negatively charged particles of thespray which tends to draw them down upon the surface of the overlying belt II.

In normal operation of this equipment a'base sheet I2 of flexible material is supported -on'the belt II and conveyed thereby through the Vspraying zone `and the plate attracted Ynegatively charged spray particles are deposited on the surface of the' sheet I2.

By proper location of the nozzles I4; I5 and I6 and proper control of the spray from lthese nozzles and exposure of the sheet 'I2 in the 'spray zone for a sucient. length of time, all as explained in the aforesaid co-pending application Serial No. 550,964, the sprayed particles deposit on the sheet I2 in irregular rough surfaced more or less individualized formations simulative of tufts or pile elements of tufted or pile carpeting and the spray surfaced .Y sheet greatly resembles `such carpeting.

In practicing this presentinvention, I; have used a belt II which is 60 inches wide'andfobtain uniform coverage of a base sheet-,I2 ofzaD- proximately belt width with a single set ofnozzles I4, I5 and I6 positioned midway ofthe widthyof the belt and locatedrespectively at'elevations .of 3l niches, 22 inches and l2 inches above the belt. The electrodes Illv are of an overalllength ofv approximately inches and the bottom of'the electrodes I8 isapproximately llf inchesabove the surface of the belt I I.

While the above .described electrostatic spray control is advantageous andA desirable because it avoids overspray and wastage of latex,theneces sary disposition of the nozzles to-discharge in a direction generally lengthwise of the electrodes I8 and of the sheet I2 results irl-building up of tuft or pile-like formations on the shee't I2 -which lean, as indicated at 34 inFig. 6; toward Hthe source of the spray. l

This is undesirable,not only fromtheistandpoint of appearancafbut also because;V the oblique application of the latex particles on :the sheet f (whichcauses the -leaningfeifecw -does not effect as firm` attachmentof the 4latex vparticles-nor as durable a wearing surface as perpendicular application thereof. Y

To overcome this disadvantage of electrostatic spray control and insure substantially perpendicular application of obliquely sprayed particles on the sheet I2, I provide means whereby the sheet I2 is progressively looped upwardly from the belt II at selected locations so as to present one side of each loop substantially directly in the path of the spray.

For this purpose idler rolls, such as indicated at 35, 36 and 31 are provided which are located at spaced intervals' along the belt II at the zone of spray application, and suiciently above the belt to preclude contact therewith.

Y These idler rolls are of metal and journaled at their opposite ends to rotate freely in bearings 38 on the side rails V3| so that these rolls are grounded through the grounded rails 3| and acquire a positive change when the generator 29 is in operation.

The sheet I2 on the conveyer belt II is laid over the rolls 35, 36 and 31 and when the spraying device is in operation and the sheet I2 is advanced with the conveyer II through the spraying zone, the sheet progressively climbs over the rolls 35, 36 and 31 successively and hugs these idler rolls closely, as indicated at 35a, 36a and 31a. These rolls, as hereinbefore indicated, turn freely in their bearings 38 and rotate with the movement of the sheet I2 thereover.

These rolls 35, 36 and 31 are all located within the zone of spray application, the rolls 35 and 31 near the entrance, and exit ends respectively and the roll 36 substantially midway therebetween, as shown, and each roll 36 and 31 is located suiiiciently beyond its respective preceding roll so that substantially the entire uprising side of the portions 36a and 31a of the sheet I2 are exposed to the spray without obstruction thereof by the preceding roll.

Spray from the lower horizontal latex nozzle I5 is deflected downwardly by the angular coagulant spray from the nozzle I6, and this, together with the charging of the latex particles by the electrodes I8 and the attraction of the plate 32 for these charged particles, causes a substantial latex deposit on the sheet I2 at the front and top of the first roll 35. 'I'herebeyond the portion of the spray from the nozzle I5 which is not intercepted by the fold 35a, and the spray from the 30 nozzle I4 are directed, by the conjoint effect of all the nozzles and the attraction of the plate 32, generally in the direction of the rolls 36 and 31 so that there is a substantial deposit of latex on the uprising portions of the sheet at the front and top of the rolls 36 and 31.

The direction of movement of the spray particles at the roller locations 35, 36 and 31 is generally substantially perpendicular to the sheet I2 at the place of impact therewith and thus the tuft or pile-like formations are built up substantially perpendicularly on the sheet I2, as indicated at 33 in Fig. 4 and the undesirable leaning or inclined arrangement of the tuft or pile-like formations which otherwise would result, as indicated at 34 in Fig. 6,- from the oblique direction 'of the spray is completely avoided.

Moreover, by reason of this perpendicular application of the spray particles to the sheet I2 a more substantial attachment of the particles to the sheet I2 and to one another results and a surfacing of superior wearing properties is assured.

Furthermore, as the sheet I2 passes over the rolls 35, 36 and 31 the curvature imparted thereto spreads apart the accumulating formations 33 and permits sucient penetration of latex particles therebetween to anchor the formations more securely in place and maintainthem more effectively in upright position.

From the foregoing it will be understood that Iv have provided an effective method and simple and convenient facilities whereby particles, which are sprayed obliquely to the plane of movement of flexible sheet material through the spraying zone, Vas in electrostatcally controlled spraying,

may be applied perpendicularly onto the sheet surface.

While I have shown and described my invention in a preferred form, I am aware that various changes and modifications may be made' therein without departing` from the principles of my invention, the scope of which is to be determined by the appended'claims.

What is claimed is:

1. In a spraying device for spraying sheet material, the combination of a horizontal conveyer for supporting and advancing the sheet, an idler roll extending transversely over the conveyer, and spraying means positioned to discharge spray therefrom in a direction lengthwise of the con-l veyer and toward one side of said idler roll, said idler roll being operable to locally deflect the sheet material upwardly from the conveyer.

2. In a spraying device for spraying sheet material, the combination of a horizontal conveyer for supporting and advancing the sheet, an idler roll extending transversely over the conveyer, spraying means positioned to discharge spray therefrom in a direction lengthwise of the conveyer and toward one side of said idler roll, said idler roll being operable to locally deect the sheet material upwardly from the conveyer, electrostatic spray charging electrodes above the conveyer and extending lengthwise thereof at opposite sides respectively of the path of the spray from said spraying means, a source of electrostatic current having poles of opposite polarity, one of which is electrically connected with said electrodes, and electrode means under said spray path and over which electrode means the sheet material is advanced by the conveyer, said electrode means being electrically connected to the other of said poles ofthe electrical energy source.

3. In the coating of flexible sheets wherein a sheet is continuously fed edgewise through a spray zone and the direction of the spray is towards the sheet, in the direction of thetravel thereof and at an acute angle thereto, the step of diverting the path of travel of the sheet from the plane thereof at a selected point in said spray zone, said sheet being diverted and conducted in a path transversely across the spray at substantially right angles thereto.

4. In the coating of flexible sheets wherein a sheet is continuously fed edgewise through a spray zone and the direction of spray is towards the sheet, in the direction of the travel thereof and at an acute angle thereto, the steps of diverting the path of travel of the sheet at selected points in said spray zone, said sheet being diverted and conducted in separate paths transversely across the spray at substantially right angles thereto and exposed to the spray.

5. In the spray coating of flexible sheets wherein a sheet is continuously fed edgewise through an electrostatic field having a spray zone therein and the direction of the spray being towards the sheet in the direction of travel thereof and at an acute angle thereto, the step of diverting the path of travel of the sheet from the plane there`` material particles moving in a direction length-` wise of and gradually approaching said path in the direction of travel of said sheet and constantly accumulating some of said particles on' said upwardly facing side of the sheet as it ad'- vances along said substantially horizontal path;

at a selected place in said spray zone continuously advancing the sheet upwardly from said substantially horizontal path along an abruptly ascending path. and aro'und a curved path to an abruptly descending path.

LUCIAN P. DOSMANN.

REFERENCES CITED- The following references are of record'in the le of this patent:

UNITED STATES PATENTSA Number Name Date Y 1,883,535 Burnett Oct. 18, 1932 2,281,558 Cross May 5, 1942 2,283,372 Kolmar May"19, 1942 2,446,953 Ransburg Aug. 10, 1948 

